From 9f9ba1fe3f8ebe999951cf64734481823a143f20 Mon Sep 17 00:00:00 2001
From: Matt Van Horn <455140+mvanhorn@users.noreply.github.com>
Date: Fri, 8 May 2026 03:15:09 -0700
Subject: [PATCH] monitor: implement system_powerdown MMP command

The QMP system_powerdown command shuts down the VM. machina has no
separate ACPI shutdown path, so dispatch reuses the existing quit()
path on MonitorService -- semantically equivalent for the embedded
monitor and consistent with how the existing "quit" command reaches
the shutdown signal.

Add a regression test in tests/src/monitor.rs that mirrors the
existing test_mmp_quit, asserting the empty success envelope and
that is_quit_requested() flips to true after dispatch.

Closes #88

Signed-off-by: Matt Van Horn <455140+mvanhorn@users.noreply.github.com>
---
 monitor/src/mmp.rs   |  9 ++++++++-
 tests/src/monitor.rs | 11 +++++++++++
 2 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/monitor/src/mmp.rs b/monitor/src/mmp.rs
index c9b4be5f..26c0c909 100644
--- a/monitor/src/mmp.rs
+++ b/monitor/src/mmp.rs
@@ -101,7 +101,7 @@ fn handle_connection(
         if cmd == "qmp_capabilities" {
             caps_done = true;
         }
-        if cmd == "quit" {
+        if cmd == "quit" || cmd == "system_powerdown" {
             return true;
         }
     }
@@ -130,6 +130,13 @@ pub fn dispatch(cmd: &str, svc: &Arc<Mutex<MonitorService>>) -> Value {
             s.quit();
             json!({"return": {}})
         }
+        "system_powerdown" => {
+            // QMP system_powerdown shuts down the VM. machina has no
+            // separate ACPI shutdown path, so reuse quit() which signals
+            // the run loop to stop -- semantically equivalent here.
+            s.quit();
+            json!({"return": {}})
+        }
         "query-cpus-fast" => {
             let cpus = s.query_cpus();
             let arr: Vec<Value> = cpus
diff --git a/tests/src/monitor.rs b/tests/src/monitor.rs
index 67f25058..8dfae9a1 100644
--- a/tests/src/monitor.rs
+++ b/tests/src/monitor.rs
@@ -137,6 +137,17 @@ fn test_mmp_quit() {
     assert!(svc.lock().unwrap().state.is_quit_requested());
 }
 
+#[test]
+fn test_mmp_system_powerdown() {
+    // QMP system_powerdown shuts down the VM. machina has no separate
+    // ACPI shutdown path, so dispatch must reuse quit() and return
+    // the empty success envelope.
+    let svc = make_svc();
+    let resp = mmp::dispatch("system_powerdown", &svc);
+    assert_eq!(resp["return"], serde_json::json!({}));
+    assert!(svc.lock().unwrap().state.is_quit_requested());
+}
+
 // ── HMP tests ───────────────────────────────────────
 
 #[test]